- Water Crafts
- Sea Doo challenger 1800
Hey guys new to the forum and located in Hampton roads Virginia. I have a 1999 Sea-Doo Challenger 1800. STBD engine is running rough, back firing coming from AFT carbonator on the rotax 787, when I remove the intake box you can see the aft carb sparking. Exhaust is pumping, but when it back fires it sucks air briefly. Cleaned the rave valves hoping to fix the issue, they had tons of carbon build up, did not fix it the issue. Checked the tourque and the exhaust system, everything was tight. Changed the spark plugs, doing the same thing, checked fuel and it's good, port engine running fine. Any thoughts?